In known subtracted angiographic x-ray image acquisition, an object of interest is typically patient vasculature. There are instances, however, where perfusion of contrast agent through capillaries is of interest. Unfortunately, such capillary perfusion is not easily visualized due to both faint appearance of the capillaries relative to larger vessels and the capillaries being obscured by the larger vessels in an image. A system according to invention principles addresses these deficiencies and related problems.